How to Fix “Unfortunately, android.process.acore Has Stopped” on Android
What “android.process.acore has stopped” means
Every Android phone runs a background process called android.process.acore. It’s the invisible service that stores and manages your contacts, your call log, and the data other apps request when they need contact information. When the pop-up “Unfortunately, android.process.acore has stopped” appears, that service has crashed — which is why the error often strikes when you open the Phone or Contacts app, and why it can keep reappearing until the underlying data is repaired.
The most common trigger is a corrupted contacts database: a failed system update, a sync conflict, or low storage interrupting a background write can leave the database in a broken state, and acore crashes every time it tries to read it. Facebook and Messenger’s contact-sync features have a long history of conflicting with Android’s native contacts database and are a classic trigger of this exact error. Glitches between your Google account and the Contacts app are another frequent cause.
The good news: this is a data problem, not a hardware problem, and your contacts are almost certainly safe. If they’re synced to your Google account, the worst case is wiping the local database and letting it re-download. Work through the steps below in order — most people are fixed by step 5.
Common causes
- Corrupted contacts database or cache: a failed update or an interrupted background write leaves the database broken, and acore crashes every time it touches it.
- Facebook or Messenger contact sync: their sync features famously conflict with Android’s native contacts database and trigger this exact crash.
- Google account sync glitch: a conflict between the account and the Contacts app poisons the data acore depends on.
- A critical system app was disabled: accidentally disabling a system component can pull the rug out from under acore.
- Low storage or outdated apps: when the phone is nearly full, background database writes fail midway; outdated Contacts or Phone apps can also mishandle the data.
How to fix “android.process.acore has stopped” — step by step
Back up your contacts before step 2 — export them to a .vcf file or confirm they’re synced to your Google account.
- Force restart the phone. Press and hold the Power button for 10–20 seconds until the device shuts off and restarts on its own (on Samsung, hold Power + Volume Down together). A forced restart clears temporary memory glitches, and that alone is sometimes all the acore process needs to recover. If the error stops here, you’re done.
- Back up your contacts, then clear the Contacts Storage data. First confirm your contacts are synced to your Google account (Settings > Accounts > your account > Account sync > Contacts), or export them: open Contacts, tap your profile, and use the export option to save a .vcf file. Then go to Settings > Apps > See all apps, tap the three-dot menu, enable Show system, and open “Contacts Storage.” Tap Storage & cache > Clear cache, then tap Clear storage to wipe the corrupted database. Restart the phone — it rebuilds the database cleanly from your sync on the next boot.
- Disable Facebook and Messenger contact sync. Open the Facebook app and go to Settings & privacy > Settings, then turn off any contact-syncing or media-contacts options. Do the same inside Messenger’s settings. Facebook’s contact sync is a long-standing trigger of this exact crash because it writes data that conflicts with Android’s native contacts database — this low-effort step resolves a meaningful share of cases.
- Reset app preferences. Go to Settings > Apps > See all apps, tap the three-dot menu, and choose Reset app preferences. This restores all apps to their default settings and automatically re-enables any disabled system apps. You may have disabled a critical system app without knowing it — resetting preferences is a safe way to undo that without deleting anything.
- Remove and re-add your Google account. Go to Settings > Accounts (or Passwords & accounts), open your Google account, and choose Remove account. Restart the phone, then go back and tap Add account > Google to sign in again. This wipes out sync glitches between the Contacts app and Google, and the fresh sync that follows often takes the error with it.
- Update the Contacts and Phone apps and the system software. In the Play Store, update the Contacts and Phone apps individually, then check Settings > System > Software update for a pending system patch. Post-update acore crashes are often fixed by the follow-up patch that vendors release shortly after.
- Factory reset as a last resort. If the error survives everything above, back up your photos, contacts, and files first, then go to Settings > System > Reset options > Erase all data (factory reset). This returns the phone to a clean state and fixes deep corruption — but everything on the phone will be wiped, so only take this step when nothing else worked.
Did this fix it? Quick checklist
- The “android.process.acore has stopped” pop-up no longer appears after restarting
- The Contacts and Phone apps open and load your contacts without crashing
- Facebook and Messenger contact syncing are turned off
- Your contacts synced back from your Google account (check Contacts to confirm)
If the error persists after a Contacts Storage clear, check Settings > System > Software update for a pending patch — post-update crashes are sometimes fixed only by the vendor’s follow-up release. And if the error started right after you installed or updated something, that something is still the best place to look.
Frequently asked questions
Is android.process.acore a virus?
No. android.process.acore is a legitimate core Android system process that handles your contacts and call log data. The error message means this process crashed — not that your phone is infected with malware.
Will clearing Contacts Storage delete my contacts permanently?
Not if your contacts are synced to your Google account or another cloud service — they re-download automatically the next time the phone syncs. If your contacts are stored only on the device, export them to a .vcf file first so you can restore them afterward.
Why did this error start right after a software update?
Updates can interrupt the contacts database mid-write or introduce a temporary incompatibility with the Contacts or Phone app. Checking for a follow-up system patch and updating the Contacts and Phone apps individually through the Play Store resolves many post-update cases.
Do I need a factory reset to fix this?
Almost never. A force restart, clearing the Contacts Storage data, disabling Facebook contact sync, resetting app preferences, and re-adding your Google account fix the vast majority of cases. Reserve the factory reset for when the error survives everything else.